The Atlanta Braves are fixin' to move out of downtown to a site in suburban Cobb County just outside the I-285 beltway once their current lease on Turner Field expires in 2016. It's odd that we're closing on the end of a 20-year lease for the stadium that was where the track events and opening/closing ceremonies were held for the 1996 Olympics.
However, the Braves' fan base skews northward into the upscale suburbs, and this move puts them closer to their economic center of gravity. Also, the Galleria area by the I-75/285 interchange has become a secondary downtown in the early 21st century, an "edge city" as urban planning scholars call them. Large cities like Atlanta form these suburban secondary downtowns as the central downtown gets too large and too unmanageable.
Atlanta's MARTA mass transit folks do have a good light-rail system going in and out of downtown (I was impressed when I used it for a teaching gig in the Sandy Springs area just off that line back in '11), but the main northern line goes more-or-less straight north whereas the proposed stadium site is more 10:30 on the dial. I've traveled that I-75/285 route quite a bit going to and from Florida in the early '00s, and the traffic there can get very messy, but downtown Atlanta is no prize, either.
Turner Field thus becomes the newest stadium to become economically obsolete, mostly due to changing demographics creating the desire to move; baseball's version of white flight might be the unkind way to put it, but this is about economics far more than it is about race, as MLB baseball grows more and more out of a blue-collar budget.